• Self-propped fractures maintain larger apertures than unpropped fractures under confining pressure, with shale particles crushing rather than embedding to preserve flow pathways.
• Increasing confining pressure expands contact areas between fracture surfaces and particles, enhancing system stability and compressive resistance.
• High stress concentrates and branches flow paths, reducing connectivity and permeability while amplifying nonlinear gas flow behavior.
• A novel sensitivity parameter m delineates stress sensitivity boundaries, revealing four characteristic regions and a permeability-strain recovery zone.